Due to the harsh environment offshore oil platforms are exposed to, it becomes necessary to sandblast and paint the structure at least once every three years. In order to gain access to the underside or superstructure, it has been necessary to build scaffolding and the like so that workmen might reach the areas which require maintenance. This approach has proved unsatisfactory. Another approach involved the placement of a conventional articulated-type crane on the deck of the station; however, this arrangement was also unsatisfactory due to the use of a large area of deck space necessary, which deck space is at a premium.
The use of lift boats, or jackup barges for use in connection with transporting equipment to and from offshore work stations or platforms is well known as is the use of conventional, articulated boom structures for placing personnel carriers such as a bucket or work platform, about and below bridges and the like for maintenance purposes. Such boom structures are operated either by hydraulic means, or by reel and cable means.
The general hydraulic electric and control equipment and functions of this type of boom structure equipment are well known in this art. Three examples of articulated and extensible boom structures are shown in U.S. Pat. Nos. 3,262,517 to Malec; 3,498,474 to Pierce, Jr.; and 4,646,875 to Sholl.